This invention relates to air conditioning and more particularly to a method and apparatus for controlling the humidity and the temperature of air through the use of solar energy.
The desirability of utilizing solar energy has been recognized. Solar energy collectors have been produced from sheets of aluminum laminated one to another, each sheet having a raised portion extending from end-to-end thereof, and matching a raised portion on the other sheet, so that the laminate has a channel extending from end-to-end through which a heat transfer fluid, usually water, can be circulated. Such a collector can be positioned so that solar radiation is intercepted by a major surface thereof, and a heat transfer fluid can be circulated through the collector channel to be heated by the intercepted solar energy. The temperature to which the heat transfer fluid is heated can be varied, within limits, by controlling the rate at which it is circulated through the collector. However, the temperature to which the heat transfer fluid is heated varies as an inverse function of the flow rate, and, it has been found, the amount of energy available from any given collector also varies as an inverse function of the discharge temperature of the heat transfer fluid. For example, slightly less than 70 percent as much energy is available from a given collector when the discharge temperature of the heat transfer fluid having a relatively low flow rate is 200.degree. F. as when the discharge temperature of the fluid at a higher flow rate is 140.degree. F., other factors being equal.
The use of energy from a solar collector in absorption refrigeration apparatus has been suggested. It has been found that available absorption refrigeration apparatus can be operated on energy from a solar collector, provided that the collector is operated to provide a heat transfer fluid at a temperature of at least about 200.degree. F., but that the absorption refrigeration apparatus will have approximately 50 percent of the capacity for which it was designed. It will be appreciated, therefore, that there is a need for more efficient ways to utilize energy from solar collectors.